Study on the cytoplasmic incompatibility in some natural population of Culex pipiens complex in China and Japan

The cytoplasmic incompatibility in the field population of Culex pipiens complex from China and Japan was studied. The results of the crossing experiments between 11 different strains suggest that some Japanese strains might be possible to be used for control Chinese strains by using male sterile technique, and the heavy infection of wolbachiae in mosquitoes may have some relations with the cytoplasmic incompatibility in the field population of Cx. pipiens complex.     

我国尖音库蚊种团抗药性现状——兼论半数致死剂量与区分剂量的关系

本文报告我国尖音库蚊种团幼虫对六种杀虫剂近年发生抗性情况,共调查16省市的32个地区。结果多数地区对有机磷酯类的敌百虫发生抗性,对马拉硫磷和杀螟硫磷抗性区较小,程度亦较低。对二二三抗药也较普遍。结果都用LC_(50)和WHO的抗性等级表示。     

油气田土壤样品中可培养丁烷氧化菌多样性研究

分别采用丁烷或丁醇选择培养法,对采自四川省达州市普光气田和湖北省江汉油田的土壤样品中的丁烷氧化菌进行了分离、纯化、16S rRNA基因序列测定及系统发育研究,探讨不同油田不同环境中烃氧化菌数量、系统发育地位以及种群多样性的差异.结果表明,初步分离获得共25株丁烷氧化菌,分属于厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)和变形菌门(Proteobacteria).2个油田样品分离出的丁烷氧化菌群落结构简单,均包括芽孢杆菌(Bacillus)、假单胞菌(Pseudomonas)、红球菌(Rhodococcus)和节杆菌(Arthrobacter)4个属的细菌,苍白杆菌属(Ochrobactrum)和分支杆菌属(Mycobacterium)的细菌分离自普光气田.普光气田分离出的丁烷氧化细菌数量和多样性略高于江汉油田.     

Does a parthenogenesis-inducing <Emphasis Type="Italic">Wolbachia</Emphasis> induce vestigial cytoplasmic incompatibility?

Wolbachia is a maternally inherited bacterium that manipulates the reproduction of its host. Recent studies have shown that male-killing strains can induce cytoplasmic incompatibility (CI) when introgressed into a resistant host. Phylogenetic studies suggest that transitions between CI and other Wolbachia phenotypes have also occurred frequently, raising the possibility that latent CI may be widespread among Wolbachia. Here, we investigate whether a parthenogenesis-inducing Wolbachia strain can also induce CI. Parthenogenetic females of the parasitoid wasp Asobara japonica regularly produce a small number of males that may be either infected or not. Uninfected males were further obtained through removal of the Wolbachia using antibiotics and from a naturally uninfected strain. Uninfected females that had mated with infected males produced a slightly, but significantly more male-biased sex ratio than uninfected females that had mated with uninfected males. This effect was strongest in females that mated with males that had a relatively high Wolbachia titer. Quantitative PCR indicated that infected males did not show higher ratios of nuclear versus mitochondrial DNA content. Wolbachia therefore does not cause diploidization of cells in infected males. While these results are consistent with CI, other alternatives such as production of abnormal sperm by infected males cannot be completely ruled out. Overall, the effect was very small (9%), suggesting that if CI is involved it may have degenerated through the accumulation of mutations.     

西双版纳南坡铜矿区植物地球化学异常特征及形成机理

对西双版纳南坡铜矿区植物与土壤地球化学剖面研究发现:发育在Ⅰ线研究剖面山脊隐伏矿床上方和山坡脚近溪流处的Ⅰ号和Ⅱ号植物综合异常,其赋存空间、物质来源及发育状态受不同成因类型的土壤异常的控制。Ⅰ号异常反映了土壤气体异常、碎屑异常和上移水成异常;Ⅱ号异常反映了土壤侧移水成异常和部分水化学异常。由于元素在植物根际环境的地球化学赋存状态及其生物有效性,植物对元素吸收的选择性和屏障效应等因素,植物中某些异常元素同土壤异常中的相应元素具有不协调性。植物地球化学异常库和所有的地球化学异常库都发生关系,它们在一定的时空、环境和动力条件下发生一系列复杂的界面反应,使元素向植物迁移转化,导致植物地球化学异常的形成。     

砂土中柴油的微生物降解研究

从加油站污染土壤中筛选出对柴油具有较强降解能力的菌株,比较研究菌株及菌群降解柴油的差异,探讨植物苜蓿和芥菜对菌株降解柴油污染物的影响.结果表明:①菌株Q18和菌群对砂土中柴油都具有较强的降解能力,菌群对柴油的降解率明显高于菌株Q18.菌株Q18 和菌群在5 d内对柴油的总降解率分别为40.29%和54.15%.与菌株Q18降解柴油相比,菌群主要是强化了中、长链烷烃化合物的降解.②在砂土中,苜蓿和芥菜都能显著地强化菌株Q18对柴油的降解,但苜蓿强化菌株Q18降解柴油的能力强于芥菜. 5 d内菌株Q18-芥菜和菌株Q18-苜蓿复合体系对柴油总降解率分别达到60.05%和56.68%.③菌群和苜蓿及芥菜复合体系降解柴油的能力也有显著提高,但芥菜强化菌群降解柴油的能力强于苜蓿.5 d内菌群-芥菜和菌群-苜蓿复合体系对柴油总降解率分别为75.53%和70.50%.      

中国出口贸易与环境目标相容性评估——基于环境效应分解模型的分析

在理论上,国际贸易既可能促进环境改善,也可能加重环境负担。在实际中,国际贸易对环境的影响最终可分解成规模效应、结构效应和技术效应。本文通过构建一个包括政府因素在内的环境效应分解模型,对中国1996年-2005年出口贸易的环境效应进行了大致估算,结果发现中国出口贸易与环境目标不相容,加重了环境负担。最后,在此基础上提出相应对策建议。     

ZE-1号印染废水脱色菌群结构与功能的研究

印染废水是水体的主要工业污染源之一。研究表明,利用微生物对印染废水进行脱色处理是一条可行的途径。浙江省环保科研所曾选育得到一组脱色性能较好,具有应用前景的混合菌群。命名为ZE-1号脱色菌群。     

Cytoskeletal elements in the bacterium Mycoplasma pneumoniae

Mycoplasma pneumoniae is a pathogenic eubacterium lacking a cell wall. Three decades ago, a "rod", an intracellular cytoskeletal structure, was discovered that was assumed to define and stabilize the elongated cell shape. Later, by treatment with detergent, a "Triton shell" (i.e. a fraction of detergent-insoluble cell material) could be obtained, believed to contain additional cytoskeletal elements. Now, by application of a modified Triton X-100 treatment, we are able to demonstrate that M. pneumoniae possesses a cytoskeleton consisting of a blade-like rod and a peripheral lining located close to the inner face of the cytoplasmic membrane, exhibiting features of a highly regular network. Attached "stalks" may support the cytoplasmic membrane. The rod was connected to the cell periphery by "spokes" and showed a defined ultrastructure. Its proximal end was found to be attached to a wheel-like complex. Fibrils extended from the proximal end of the rod into the cytoplasm.     

北京市地铁站站台空气微生物抽样检测的实验研究

采取新旧地铁站台对比研究的方法选取三个有代表性的换乘站的六个站台,分别研究各站台空气中细菌、真菌的含量,并做浅要分析。结果表明：旧站台在细菌数上远比新站台高,而真菌数却明显比新站台低（一号线东单站站台例外）。菌落总数只有2号线复兴门站站台超过2500cfu／m^3,达2883cfu／m^3;再则是1号线复兴门站站台接近2500cfu／m^3,为2092cfu／m^3,其余诸站台均明显低于2500cfu／m^3。这表明北京市地铁站站台空气微生物的质量比较好。对菌种进行初步分析知细菌的优势菌种为球菌（金黄色葡萄球菌、双球菌）和杆菌,真菌的优势菌种为青霉属和黄曲霉属。     

Study on the wind field and pollutant dispersion in street canyons using a stable numerical method

A stable finite element method for the time dependent Navier-Stokes equations was used for studying the wind flow and pollutant dispersion within street canyons. A three-step fractional method was used to solve the velocity field and the pressure field separately from the governing equations. The Streamline Upwind Petrov-Galerkin(SUPG) method was used to get stable numerical results. Numerical oscillation was minimized and satisfactory results can be obtained for flows at high Reynolds numbers. Simulating the flow over a square cylinder within a wide range of Reynolds numbers validates the wind field model. The Strouhal numbers obtained from the numerical simulation had a good agreement with those obtained from experiment. The wind field model developed in the present study is applied to simulate more complex flow phenomena in street canyons with two different building configurations. The results indicated that the flow at rooftop of buildings might not be assumed parallel to the ground as some numerical modelers did. A counter-clockwise rotating vortex may be found in street canyons with an inflow from the left to right. In addition, increasing building height can increase velocity fluctuations in the street canyon under certain circumstances, which facilitate pollutant dispersion. At high Reynolds numbers, the flow regimes in street canyons do not change with inflow velocity.     

Modeling of secondary treated wastewater disinfection by UV irradiation: Effects of suspended solids content

This work aimed to study UV-resistant strains of Pseudomonas aeruginosa, to propose a formulation of the kinetics of secondary treated wastewater disinfection and to underline the influence of suspended solids on the inactivation kinetics of these strains. Some investigations were carried out for the validation of some simulation models, from the simplest, the kinetics model of Chick-Watson reduced to first order, to rather complex models such as multi-kinetic and Collins-Selleck models. Results revealed that the involved processes of UV irradiation were too complex to be approached by a simplified formulation, even in the case of specific strains of microorganisms and the use of nearly constant UV radiation intensity. In fact, the application of Chick-Watson model in its original form is not representative of the kinetics of UV disinfection. Modification, taking into account the speed change during the disinfection process, has not significantly improved results. On the other hand, the application of Collins-Selleck model demonstrates that it was necessary to exceed a least dose of critical radiation to start the process of inactivation. To better explain the process of inactivation, we have assumed that the action of disinfectant on the survival of lonely microorganisms is faster than its action on suspended solids protected or agglomerated to each others. We can assume in this case the existence of two inactivation kinetics during the processes (parallel and independent) of the first-order. For this reason, the application of a new kinetic model by introducing a third factor reflecting the influence of suspended solids in water on disinfection kinetics appeared to be determinant for modeling UV inactivation of P. aeruginosa in secondary treated wastewater.     

变电站复杂声场中多点噪声源的鉴别

复杂声场中单个声源的鉴别和评价是噪声污染控制的重要环节。简要介绍了几种常用的噪声源鉴别方法,然后结合变电站复杂声场中噪声产生的实际情况,针对变电站主要声源噪声的特性提出了两种方法的基本原理和具体操作步骤,即声强测量法和基于波叠加的噪声源识别方法,用以进行变电站中多点噪声源的鉴别。这为建立变电站声场中多点声源鉴别的标准方法提供了可能;对于厂界噪声超过环保部门确定标准的变电站,应用这些方法可以提供明确的治理思路。     

The environmental challenges in Sub-Saharan Africa

Countries in sub-Saharan Africa are doing some rethinking, after decades of development that have resulted in continued poverty, international indebtedness, environmental degradation, and inappropriate Western models. Technological innovations, institutional developments, and family planning are key inputs. Development should shift to a focus on elimination of widespread poverty. Past development strategies in an African context of ample resources have harmed the environment without improving the average person's standard of living. Knowledge about Africa's environment and environmental degradation is inadequate. Recent studies have found, contrary to popular belief, that small shareholders made considerable investments in resource-based capital, which protected their farms from major environmental deterioration and negative impacts of intensification. In Nigeria field studies found that rising demand for fuelwood did not lead to greater deforestation or desertification. Severe degradation has occurred in places where density of population is greater than 500 persons per sq. km, where the land is physically or biologically vulnerable, and where socioeconomic conditions interfere with application of conservation measures. Reduced well-being and reduced food capacity is attributed to land tenure arrangements, misguided macroeconomic policies, and inadequate infrastructure. The issues of development, environment, and population are complex. Sustainable development is possible with appropriate investment priorities that will provide needed infrastructure, services, and education. Urban areas need safe water, solid waste disposal, and spatial planning to relieve congested spaces. Rural areas should focus on health education and basic sanitation. Regulatory measures and conservation measures are also important. Institutional development that promotes democracy, expands individual property rights, and increases the knowledge base offers the most hope for alleviating poverty and protecting the environment.     

氯酚污染土壤的生物强化修复及其微生物种群动态变化的分子生物学监测

在氯酚污染的土壤中接种氯酚降解菌,研究了受污染土壤的生物强化修复.利用传统的微生物计数方法和现代分子生物学手段,研究了生物强化修复过程中微生物种群的动态变化情况.在受氯酚污染的土壤样品中,以氯酚为唯一碳源和能源,分离出了多株对氯酚具有较高降解能力的微生物,利用16S rDNA序列分析方法对部分微生物进行了种属鉴定.土壤中存在的土著的氯酚降解菌可以对低含量的氯酚(100mg·g-1)进行降解;但是当土壤中氯酚含量较高(500 mg·g-1)时,土著微生物的降解能力受到限制,这可能是高浓度的氯酚对土著的氯酚降解菌会产生毒性作用.接种外来微生物后,土壤中可以培养的氯酚降解菌的总数从开始的106CFU·g-1增加到108CFU·g-1,并且,在氯酚含量为100 mg·g-1的土壤样品中,微生物数目的增加比在氯酚含量为500 mg·g-1土壤样品中更快.这表明接种的外来微生物可以在土壤中很好地生长繁殖,有效地促进土壤中氯酚的生物降解.接种外来微生物可以减轻土壤中氯酚对土著微生物初期产生的不利影响.土壤中的氯酚可能会改变微生物种群结构.DGGE分析结果表明,在未受氯酚污染和受氯酚污染的土壤样品中,存在一些共同的DNA谱带,但谱带强度有明显的差异.在受污染的土壤中接种外来微生物进行生物强化,可以促进污染物的生物降解过程,是生物修复过程中的一种重要手段,有着广泛的应用前景,将在我国受污染环境的生物修复中发挥重要作用.     

Microbial diversity of soil bacteria in agricultural field contaminated with heavy metals

In this study we evaluated the bacterial diversity in a soil sample from a site next to a chemical industrial factory previously contaminated with heavy metals. Analysis of 16S rDNA sequences amplified from DNA directly extracted from the soil revealed 17 different bacterial types （genera and/or species）. They included Polyangium spp., Sphingomonas spp., Variovorax spp., Hafina spp., Clostridia, Acidobacteria, the enterics and some uncultured strains. Microbes able to tolerate high concentrations of cadmium （500μmol/L and above） were also isolated from the soil. These isolates included strains of Acinetobacter （strain CD06）, Enterobacter sp. （strains CD01, CD03, CD04 and CD08） （similar strains also identified in culture-independent approach） and a strain of Stenotrophomonas sp. The results indicated that the species identified from direct analysis of 16S rDNA of the soil can be quite different from those strains obtained from enrichment cultures and the microbial activities for heavy metal resistance might be more appropriately addressed by the actual isolates.     

粒子图像测速技术在往复隔板絮凝池中的应用

由于往复隔板絮凝池廊道狭窄、絮凝池拐弯水流结构复杂,致使整个流场的量测十分困难。采用了粒子图像测速技术,对其流场进行了量测与相关分析,提高了分析结果的准确性和可靠性。     

紫外辐射增强对麦二叉蚜发生量的影响

研究春小麦大田栽培自然光条件下,模拟紫外辐射（ＵＶ－Ｂ,２９０￣３１５ｎｍ）分别增加２．５４、４．２５及５．３１ｋＪ·ｍ＾－２对小麦（寄生虫麦二叉蚜（Ｓｃｈｉｚａｐｈｉｓ ｇｒａｍｉｎｕｍ）的发生、种群密度、繁殖系数等方面的影响。结果表明麦二叉蚜的种群密度与其当年的发生量密切相关,并且种群密度随着ＵＶ－Ｂ辐射强度的增加明显降低,但对麦二叉蚜的繁殖特性没有显著的抑制作用。因此认为,未来臭氧层减薄紫外     

区域生态环境质量评价研究综述

随着社会进步、经济发展和人民生活水平不断提高,环境恶化与生态环境破坏的问题日益严重,人口、资源与环境的矛盾日益尖锐,环境问题特别是生态环境质量已成近年来的研究热点。在综合国内外研究的基础上,介绍了生态环境评价的相关概念,阐述了生态环境质量评价指标体系的发展,列举了生态环境质量评价的常用方法,并指出了现阶段环境质量评价工作的不足及其未来的发展方向。     

一株异养脱氮菌的分离及脱氮性能研究

经过野外采样、稀释平板法、富集培养等步骤进行初步筛选得到12株菌,并通过测定其对NH4+-N去除效果,复筛得到1株对NH4+-N去除率最高的菌株,命名为Y8。该菌株为革兰氏阴性杆状菌。通过小试的初步研究,考察了不同碳源、温度、pH值、摇床转速对Y8去除NH4+-N的影响,实验结果表明:Y8在以丁二酸纳为唯一碳源、温度30℃、pH值9.5、转速150 r/min条件下去除NH4+-N效果最好;并且在有氧情况下对NO3--N和NO2--N均有一定去除效果。